JPS6026519B2 - Base material for friction materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in asbestos-free base materials for friction materials such as clutch facings and brake linings.

More specifically, the present invention relates to an improvement in an asbestos-free friction material base material that has significantly improved judder resistance, friction properties, etc. compared to conventional asbestos-free friction materials. Friction materials such as clutch facings and brake linings (hereinafter referred to as friction materials) are made of inorganic fibrous materials such as asbestos, glass fiber,
It consists of organic fibrous materials such as polyimide fibers, wear-resistant powder made by thermosetting natural alkylphenols, and metal wires, and uses formaldehyde condensation resins such as phenol and melamine as binders. It is molded.

The friction material manufactured in this way is an important part of an automobile, and needs to have excellent friction properties during driving, anti-judgement properties, and the like.

Conventional friction materials are manufactured using asbestos fiber as a base material.

However, since this type of friction material is based on asbestos, which is harmful to the human body, it has the disadvantage of deteriorating the working environment and having a negative impact on workers, and is subject to various regulatory measures before being used as a raw material. It has become possible to do so. Therefore, in recent years, efforts have been made to develop friction materials that do not use asbestos. Various materials are being considered as substitutes for asbestos, but glass fiber is the most representative material due to its properties and price. However, in the case of glass fiber, the average thickness is usually 9~
It is as thick as 20 m, and its surface is not uneven like asbestos, making it extremely difficult to incorporate wear-resistant powder and having poor adhesion to the binder. Therefore, friction materials using glass fiber as a base material have inferior friction properties than conventional friction materials using asbestos as a base material. It is an object of the present invention to provide a base material for a friction material that eliminates all of the above-mentioned drawbacks and has an effect equivalent to or better than that of conventional friction materials made of asbestos.

As a result of various studies on the above-mentioned drawbacks, the inventors of the present invention found that organic fibers to which wear-resistant powder was attached or dispersed were twisted into single yarns, and then combined with bulk-processed glass fibers and metals. When the friction material was produced, it was possible to eliminate all of the drawbacks of conventional asbestos-free friction materials, and to produce an asbestos-free friction material that has the same effects as conventional friction materials. The present invention relates to a base material for friction materials, which is made by twisting organic fibers to which wear-resistant powder is attached or dispersed to form single yarns, and co-combusting them together with bulky processed glass fibers and metals.

In addition, in the present invention, bulk processing refers to
It has the crimp form of natural fibers, such as wool, and improves the texture of glass fibers and other materials to improve elasticity and bulk.
It is a process that imparts character.

Types of glass fibers include E glass, A glass, C glass, S glass, and G glass, and there are no particular restrictions on their use.

The organic fibers that can be used include wire, rayon fiber, aromatic polyamide/imide fiber, and cotton cloth, and the metals that can be used are shinchi, zinc, aluminum, magnesium, etc., and these can be used as they are cotton. There are no restrictions even if it is used in powder form.

As the wear-resistant powder, phenol, alkyl phenol, hardened cashew shell oil-based resin, etc. are used.

It is preferable to include the wear-resistant powder in an amount of 6 to 5% by weight in the yarn obtained by co-combusting organic fibers, glass fibers, and metals, since this provides excellent judder resistance and friction properties. In addition to the above components, inorganic fibers such as carbon fibers and ceramic fibers may be used in combination, if necessary.

During long-term storage, friction materials such as clutch facings and mating materials (flywheel or pressure plate)
However, even in such a state, there must be no rust or adhesion between the clutch facing and the mating material, and smooth operation must be possible even when starting to use after long-term storage. For this purpose, a metal wire or metal powder of zinc, aluminum, magnesium, etc., which can be used as a sacrificial iron anode, may be used, or it may be thermally sprayed onto the surface of the friction material. In addition to this, rust prevention treatment may be performed by soaking the friction material in a sodium nitrite-based rust prevention liquid and drying it. The present invention will be explained below with reference to Examples.

Example 1 Thermoset cashew shell oil (manufactured by Tohoku Kako, trade name FF1600) in an amount of 2% by weight based on the yarn was dispersed in a cloth, and then twisted using a seishigami machine to form a yarn with a diameter of 1.
．． I made it a single thread of an enemy.

Separately from the above, a total of 800 E-glass single fibers having a fiber diameter of 12 mm were converged to form a strand, and then the strand was pulled together and subjected to bulk processing. Next, one of the above-mentioned single threads, two glass fibers with a basket height of 12 mm in diameter, one thin wire with a diameter of 0.16 and one wire with a diameter of 0.19
One piece of zinc wire on the gunwale is combined with yarn to become the base material for friction material (
A) was obtained.

Next, melamine resin (manufactured by Hitachi Chemical,
Product name VU-571N) was mixed with 2% by weight, and then 1
After drying at 0 for 5 minutes, the temperature was 160 qo and the pressure was 5.
Heat and pressure molding was carried out under the conditions of 0k9f/ground, and then hardening was carried out in a mold for 30 minutes.

Thereafter, it was heat treated at 200:00 for 4 hours and the surface was polished to obtain a clutch facing (A). Example 2 Thermoset cashew shell oil (manufactured by Tohoku Kako, trade name: FF1600) in an amount of 1% by weight based on the yarn was dispersed in a cloth, and then twisted using a grain grader to obtain a yarn with a diameter of 1%.
．． It was made from a single yarn made from Cape Mizuki.

Separately from the above, 800 E-glass single fibers having a fiber diameter of 121 m were converged to form a strand, and the strand was then pulled together and subjected to bulk processing. Next, one of the above-mentioned single yarns, two glass fibers with a basket height of 12 m in diameter, one shinchiyu wire with a diameter of 0.16 ribs, and a wire with a diameter of 0.19
A single zinc wire from Misaki is combined with yarn to become the base material for friction materials (
B) was obtained.

Next, the yarn (B) was impregnated with 2% by weight of a phenol resin (manufactured by Hitachi Chemical, trade name: PRX553), and the same steps as in Example 1 were carried out to obtain a clutch facing (B).

Comparative Example 1 Clutch facing (
C) was obtained.

Comparative Example 2 The fabric was twisted by a spinning machine to a diameter of 1. Obtain a single yarn of the roost, and use this single yarn, the bulk-processed glass fiber IZ with a diameter of 12 mm obtained in Example 1, one shinchiyu wire with a diameter of 0.16 mm, and a single yarn with a diameter of 0.1 mm. A yarn (C) was obtained by combining it with one piece of zinc wire of 1 kalpa.

Next, an attempt was made to mix thermoset cashew shell oil (manufactured by Tohoku Kako, trade name FF1600) into the yarn (C), but since it could only be mixed in at a maximum of 2% by weight, the thermoset cashew shell oil was mixed into the yarn (C). Yarn (D) containing 2% by weight was obtained.

Thereafter, the same steps as in Example 1 were carried out to obtain a clutch facing (D). Comparative Example 3 Using asbestos instead of bulky glass fiber,
Other than that, a clutch facing was obtained through the same formulation and the same steps as in Example 1.

Example 1, Example 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3
Various tests were conducted on the clutch facings obtained. The results are shown in Table 1. Table 1 The friction coefficient and wear rate were measured using a constant speed friction tester.

The test conditions are as follows. o Test conditions Distance between test piece center and rotation axis center: 0.15 Disk: FC25 Rotation speed: 50 pm (rotation) Test piece: 25 positions x 25 sides x thickness 3.5 skin → 2 pieces Surface pressure :
5k9f/friction direction: Regarding the bending strength in the friction direction of the facing, the distance between the supports was set at 4 kami, and the maximum load and deflection at failure of the test piece were measured.

In addition, judder resistance was measured by installing a clutch facing on a Skyline car (manufactured by Nissan Motor Co., Ltd.) and measuring the longitudinal vibration of the car body using an accelerometer. As a result of the test, the clutch facings of the present invention in Examples 1 and 2 were found to have better friction coefficients and wear rates than the conventional clutch facings made of asbestos instead of bulky glass fiber (Comparative Example 3). Effects equivalent to those obtained were obtained, and even greater effects were obtained in terms of bending strength and anti-jadder properties.

On the other hand, it was confirmed that the clutch facings of Comparative Examples 1 and 2 had defects in either the friction coefficient, wear rate, bending strength, or judder resistance. Regarding the bell attachment, no fin formation was observed no matter which clutch facing was used.

Although the present invention has been described for the case where it is applied to clutch facings, similar effects can be obtained also for friction materials such as disc pads and brake linings.

The base material for friction materials according to the present invention is made by twisting organic fibers to which wear-resistant powder is attached or dispersed to form single yarns, and combining them with bulky glass fibers and metals, thereby eliminating all the drawbacks of the conventional ones. However, it is possible to obtain effects equivalent to or better than conventional friction materials made of asbestos.

Claims (1)

[Claims] 1. A base material for friction materials made by twisting organic fibers to which wear-resistant powder is attached or dispersed to form a single system, and then twisting them together with bulky glass fibers and metals.